NIS - libdoc.who.int - World Health Organization

WHO monographs on medicinal plants commonly used in the Newly Independent States (NIS)
Precautions
Drug interactions
Patients on warfarin therapy should be warned that garlic supplements
may increase bleeding times. Blood clotting times have been reported to
double in patients taking warfarin and garlic supplements (130).
Carcinogenesis, mutagenesis, impairment of fertility
Bulbus Allii Sativi is not mutagenic in vitro (Salmonella microsome reversion
assay and Escherichia coli) (131, 132).
Pregnancy: non-teratogenic effects
There are no objections to the use of Bulbus Allii Sativi during pregnancy
and lactation.
Nursing mothers
Excretion of the components of Bulbus Allii Sativi into breast milk and its
effect on the newborn has not been established.
Other precautions
No general precautions have been reported, and no precautions have been
reported concerning drug and laboratory test interactions, paediatric use,
or teratogenic or non-teratogenic effects on pregnancy.
Adverse reactions
Bulbus Allii Sativi has been reported to evoke occasional allergic reactions
such as contact dermatitis and asthmatic attacks after inhalation of the
powdered drug (133). Those sensitive to garlic may also have a reaction to
onion or tulip (133). Ingestion of fresh garlic bulbs, extracts, or oil on an
empty stomach may occasionally cause heartburn, nausea, vomiting, and
diarrhoea. Garlic odour from breath and skin may be perceptible (7). One
case of spontaneous spinal epidural haematoma, which was associated
with excessive ingestion of fresh garlic cloves, has been reported (134).
Posology
Unless otherwise prescribed, average daily dose is as follows (7): fresh
garlic, 2–5 g; dried powder, 0.4–1.2 g; oil, 2–5 mg; extract, 300–1000 mg
(as solid material). Other preparations should correspond to 4–12 mg of
alliin or about 2–5 mg of allicin).
Bulbus Allii Sativi should be taken with food to prevent gastrointestinal
upset.
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